Validation of a quantitative assay of arbutin using gas chromatography in Origanum majorana and Arctostaphylos uva-ursi extracts.

Abstract

Arbutin is a skin-whitening agent that occurs naturally in the bark and leaves of various plants. It is commonly quantified in plant extracts and skin-whitening products by HPLC. To develop an alternative gas chromatographic method for the separation and quantification of arbutin in Origanum majorana and Arctostaphylos uva-ursi extracts. N,O-Bis(trimethylsilyl)acetamide and trimethylchlorosilane were used as silylation reagents, and the gas chromatographic separation of silylated extracts and standards was performed using a DB-5 narrow bore column. GC-MS was used for the compound identification, and the quantification was carried out by GC-FID. The quantitative results were compared with those of HPLC analysis. The developed method gave a good sensitivity with linearity in the range 0.33-500 mg/mL and recovery >98%, allowing the quantification of arbutin in O. majorana and A. uva-ursi extracts. The relative standard deviations (RSD) relating to intra-day and inter-day precision were <0.002% and <4.8%, respectively. The GC results correlated well with those obtained by HPLC analysis. The analysis of marjoram and bearberry samples showed that the established GC method was rapid, selective, and demonstrated that arbutin could be screened alternatively by gas chromatography.